Machine, tool, and method of resizing pistons and the like



May 11, 1954 H R PH L 2,677,977

MACHINE, TOOL, AND METHOD RESIZING PISTONS AND THE LIKE Filed Nov. 61951 2 Sheets-Sheet l INVENTOR.

MACHINE,

Filed 1951 H. P. PHILLI TOOL, AND M T O F RESIZING PISTONS AND E LIKE 2Sheets-Sheet 2 I! \jz 4i 3% Z/ %d INVENTOR.

Patented May 11, 1954 MACHINE, TOOL, AND METHOD OF RESIZ- ING PISTONSAND THE LIKE Harold P. Phillips, Hastings, Mich., assignor to HastingsManufacturing Company, Hastings,

Mich.

Application November 6, 1951, Serial No. 255,071

8 Claims.

This invention relates to improvements in a machine, tool and method ofresizing pistons and the like.

The main objects of this invention are:

First, to provide a machine for resizing internal combustion enginepistons by knurling the wall thereof.

Second, to provide a machine for this purpose in which the knurled areaor surface is very uniformly enlarged and presents a relatively largeperipheral Wear surface or area.

Third, to provide a machine for expanding or resizing pistons which doesnot require a highly skilled operator.

Fourth, to provide a knurling tool which is highly eflicient forproducin diamond knurls while permittin the work to be driven with areciprocating or oscillating stroke.

Fifth, to provide a method of resizin pistons which results in a uniformquality of work and in producing a uniformly expanded area having adesirable wearing surface.

Objects relating to details and economies of the invention will appearfrom the description to follow. The invention is pointed out in theclaims.

A preferred embodiment of the invention is illustrated in theaccompanying drawings, in which:

Fig. 1 is a perspective view of a machine embodying the invention withan internal combustion engine piston mounted thereon and showing aninitial work stroke.

Fig. 2 is a horizontal cross sectional view of the machine with theparts in the position shown in Fig. 1.

Fig. 3 is an enlarged fragmentary view, the piston being shown invertical section with a knurling tool'in operative relation thereto.

Fig. 4 is an enlarged fragmentary view of the that it has beenpreviously proposed to resize or alter the effective diameter of pistonsof an internal combustion engine by knurling portions of the side wallsof the pistons. In the machine of my said application the knurling is inthe form of a series of parallel lines of knurling cuts which areproduced by a knurling cutter having teeth extending diagonally or in aninclined relation to its axis.

The machin and cutter of the present application is designed to producea continuous knurl of a diamond pattern. A knurled piston or piece ofwork i is shown. in Fig. 6, the knurled surface thereof being shown at2. Fig. 7 is a diagrammatic illustration of the manner in which themachine operates to produce the diamond patterned knurled resizedsurface in which the diamond-shaped parts 3 are raised relative to thesurface of the area prior to knurling.

The machine illustrated comprises a base 4 which is designed to bemounted on a suitable support such as a bench or platform. The basecarries the main upright 5 and an auxiliary upright 6 which is disposedin parallel relation to the main upright. These uprights are connectedat their upper ends by the crosspiece 1. The headstock 8 is providedwith a work chuck 9 havin work clamping jaws H3. The details ofadjusting the jaws form no part of the present invention and aretherefore not illustrated herein.

The chuck or headstock is designed for supporting diiferent sizes ofpistons. The chuck is provided with a double crank arm il havingdiametrically opposite wrist pins 12. The chuck is oscillated from theelectric motor i3 which is connected through suitable reducing gearindicated at It in Fig. 2 to the crank disc i5 having a radial slot I6therein adjustably receiving the crank pin i1, and the pitman orconnecting rod I8 engaged with on or the other of the wrist pins I2.With this arrangement the chuck is driven with an oscillating movement,the length of the oscillating stroke bein determined by the position ofthe crank pin it radially of the crank disc.

To center and steady the work in coacting relation to the jaws it Iprovide a tailstock comprising a centering work engagin cone iii towhich the quill or screw 29 is rotatably connected. ihe tailstock isprovided with a steady bar 2i which has rollers 22 and23 at its endscoacting with the uprights 5 and ii. The screw or quill 23 has threadedengagement with the nut Ii carried by the crosspiece "l. The verticaladjustment of the tailstock permits the machine to accommodate pistonsof different lengths and securely clamps the work upon the chuck. It iscontemplated that the cone members l9 of different sizes will beprovided to coact with a wide range of piston diameters. The conicalshape enables it to engage work of diameters which do not exceed therange of the particular cone. A thrust bar 12 is provided for the screw20.

The knurling tool holder 24 is carried by an arm 25 swingably andslidably mounted on the upright and provided with an elongated hearing26. The arm is vertically adjusted by means of the cable 21 which ismoved over the pulley 28 journaled at 29 on the upper end of the upright5, the pulley being provided with a lever or handle 33 for rotating it.The cable is wrapped around the pulley and its end 3| provided wtih acounterweight (not illustrated) The tool holder 24 is longitudinallyslotted at 32 to engage the stud 33 having a clamping nut 34 thereon.

The tool holder 2 has a longitudinal slot 35 opening at its inner endand of a width to receive anrl laterally support the pair of cutters 36.These cutters 36 are independently rotatable upon the pin 3'. and are ofuniform thickness and disposed in side by side relation. These cuttersare of the same diameter and are provided with oppositely inclined teeth38. The teeth are of the same shape and the same spacing. Theoscillating stroke of the chuck or headstock has been described.

The tool is fed to the work by means of the feed nut 40 and the screw 4!which passes through a boss 42 on the end of the arm 25. The spring 43on the screw biases the arm 25 outwardly. The screw 4| is slidablymounted on the upright 6 at 44. The boss 42 carries a pointer 15coacting with graduations on the feed nut 40. A setscrew 46 is providedfor clamping the arm bearing member 28 to the upright 5 which may bedesirable in adjusting the machine to the work.

With the work in the machine the tool holder is properly adjusted andthe tool pressed against the work with initial driving pressure for theadjustment of the feed nut 49. The motor is then started (the motorcontrol not being illustrated) which oscillates the work through thepredetermined stroke, the stroke being determined by the positioning ofthe crank pin l1, and. the feed nut is adjusted to secure the desireddepth of cut.

When the desired depth of cut is secured the tool is adjusted axially ofthe work. The result is that a diamond pattern is cut or formed on acontinuously knurled surface as shown at 2 in Fig. 6. The workman soonacquires the necessary skill to determine the proper depth of cut and tofeed the tool axially of the work. This in practice is readilydetermined by the feel although if desired a gauge or gauging indiciacan be provided. That, however, is not illustrated as the machines incommercial use are not equipped with that feature.

During the reversal of the stroke and the feeding of the knurling toolaxially of the work the tool is kept under constant cutting pressure.The cutters are shown in Fig. 3 with their teeth in register but this isnot necessary to produce the diamond-shaped knurls as isdiagrammatically shown in Fig. 7. It is necessary in maintaining thepattern that the contact of the tool be maintained with the work as thework is oscillated. In effect the cuts of the teeth of one cutter crossthe cuts of the teeth of the other cutter.

The machine illustrated is highly practical for the practice of themethod of the invention. The knurled surface thus produced presents amultiplicity of raised diamond-shaped areas and results in veryuniformly increasing the diameter of the treated area. After one side ofthe piston has been knurled the knurling tool is disengaged from thepiston, the pitman or connecting rod disconnected from the pin l2, thechuck turned and the pitman engaged with the other pin 12. It should benoted that only one chucking operation is required for each piston.

I have illustrated and described a highly practical machine forperforming the method of my invention and my improved knurling tool. Ihave not attempted to illustrate various forms or variations of themachine as it is believed that this disclosure will enable those skilledin the art to embody or adapt the invention as may be desired.

Having thus described my invention, what I claim as new and desired tosecure by Letters Patent is:

1. In a machine for knurling pistons, the combination of an upright, arotatable work chuck disposed with its axis in spaced parallel relationto said upright, driven means for oscillating said work chuck, a toolcarrying arm mounted on said upright for vertical sliding and swingableadjustment thereon, a tool holder mounted on said arm for longitudinaladjustment and radially relative to the axis of the work, manuallyadjusted tool feed means for said arm, manually actuated means forvertically adjusting said tool carrying arm on said upright forpositioning the tool carried thereby longitudinally relative to thework, and a knurling tool mounted on said tool holder and comprising apair of disc-like cutters of the same diameter disposed in side by sidecontacting relation, and independently rotatable on the same axis, saidcutters having equally spaced elongated teeth, the teeth of one cutterbeing oppositely inclined relative to the other so that the teeth of thecutters are aligned so they coact in producing V-shaped cuts in the workas they are translated relative to the work.

2. In a machine for knurling pistons, the combination of an upright, arotatable work chuck disposed with its axis in spaced parallel relationto said upright, driven means for oscillating said work chuck, a toolcarrying arm mounted on said upright for vertical sliding and swingableadjustment thereon, a tool holder mounted on said arm, manually adjustedtool feed means for said arm, manually actuated means for verticallyadjusting said tool carrying arm on said upright for positioning thetool carried thereby longitudinally relative to the work, and a knurlingtool mounted on said tool holder and comprising a pair of disc-likecutters of the same diameter disposed in side by side contactingrelation, and independently rotatable on the same axis, said cuttershaving equally spaced elongated teeth, the teeth of one cutter being0ppositely inclined relative to the other so that the teeth of thecutters are aligned so they coact in producing V-shaped cuts in the workas they are translated relative to the work.

3. A knurling tool comprising a cutter holder having a slot opening atits inner end, a bearing pin extending transversely of the slot, and apair of disc-like cutters disposed in side by side contacting relationand independently rotatable on said pin, said cutters being of the samediameter and having equally spaced elongated axial- 1y inclined teeth,the teeth of one cutter inclined oppositely from those of the othercutter.

4. A knurling tool comprising a cutter holder, a bearing pin on saidholder, and a pair of disclike cutters disposed in side by sidecontacting relation and independently rotatable on said pin, saidcutters being of the same diameter and having equally spaced axiallyinclined outwardly tapered elongated teeth extending from edge to edgethereof, the teeth oi one cutter being inclined oppositely to the teethof the other cutter.

5. A knurling tool comprising a cutter holder, a bearing pin on saidholder, and a pair of disclike cutters disposed in side by sidecontacting relation and independently rotatable on said pin,

said cutters being of the same diameter and having equally spacedelongated axially inclined teeth, the teeth of the cutters beinguniformly spaced and oppositely inclined relative to the axis of theiraxis of rotation whereby when the cutter is translated to the work thecutters coact to produce V-shaped angled cuts in the work.

6. A knurling tool comprising a cutter holder, and a pair of axiallyaligned cutters mounted on said holder, said. cutters being or the samediameter and having equally spaced axially inclined elongated teeth, theteeth of one cutter being oppositely inclined from the teeth of theother cutter, said cutters being independently rotatable so that theteeth are free to align when translated upon and relative to the workand the cutters coacting to provide V-shaped cuts at each suchtranslation.

7. In a machine for knurling pistons, the combination of an oscillatablework chuck, means for oscillatingly driving said work chuck with strokesless than 360 degrees in length, a tool holder mounted for adjustmentaxially of the work, manually actuated means for adjusting said toolholder for positioning a tool carried thereby axially of the work, toolfeed means for adjusting said tool holder to and from the workindependently of the aforesaid axial adjustment thereof, and a knurlingtool rotatably mounted on said tool holder with its axis parallel to theaxis of the work chuck and comprising a pair of independently rotatableaxially aligned cutters of the same diameter disposed in side by sidecontacting relation and having equally spaced elongated axially inclinedteeth, the teeth of one cutter being inclined oppositely from the teethof the other cutter and at the same angle so that the two cutters coactwhen the adjacent ends of the teeth are aligned in forming a series ofangled cuts as the work is oscillatingly translated relative to thecutters.

8. In a machine for knurling pistons, the combination of a rotatablework chuck, means for oscillatingly driving said work chuck, a toolholder mounted for adjustment axially of the work, manually actuatedmeans for adjusting said tool holder for positioning a tool carriedthereby axially of the work, tool feed means for adjusting said toolholder radially of the work in its several positions of axial adjustmentrelative to the work and independently of the aforesaid axial adjustmentthereof and while the work is being oscillatingly driven, and a knurlingtool rotatably mounted on said tool holder with its axis parallel to theaxis of the work chuck and comprising a pair of independently rotatableaxially aligned cutters of the same diameter disposed in side by sidecontacting relation and having equally spaced elongated axially inclinedteeth, the teeth of one cutter being inclined oppositely from the teethof the other cutter and at the same angle so that the two cutters coactwhen the adjacent ends of the teeth are aligned in forming a series ofangled cuts as the work is oscillatingly translated relative to thecutters.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 934,335 Nahm et al Sept. 14, 1909 1,369,792 Djidics Mar. 1,1921 1,623,662 Dover Apr. 5, 1927 1,877,530 Read Sept. 13, 19322,335,316 Shepard Nov. 30, 1943

